Pump structure for oil burners



Feb. 16, 1943. R, E, NEsT 2,311,461 y PUMP STRUCTURE FOR on. BURNERS Y' Filedl April 14, 1941 '2 Sheets-Sheet 1 Feb. I6, 1943. R. E.'NEsT' 2,311,461

PUMP STRUCTURE FOR OIL BURNERS Filed April 14, 1941` 2 Sheets-Sheet 2 26' l 3mm wl'acHARoE'. Nes-r f Patented Feb. 16, 1943 PUMIP STRUCTURE FOR OIL BURNERS {Richard E.

Claude W.

Nest, Baltimore, Md., assignor to Schaefer, doing business as GeneraL Oil Burner Company, Baltimore, Md. Application April 14, 1941, serial No. 388,432

(chloe-87) 15 Claims.

This invention relates to a vertical rotary oil burner and it has specific reference to the fuel pumping and lubricating means. The installation illustrated is designed for domestic use although the invention is not limited to such installations.

The objects of the invention are to simplify the pumping structure so that both fuel and air are fed to the burner by a single motor without the interposition of any gearing or other parts which not only sometimes get out of order but which are so inaccessible. The whole burner head, rotor and pump assembly is removable from the burner as an integral unit after simply removing the top burner plate and it may be replaced with equal facility without requiring tools or any adjustment whatsoever.

Another object of the invention is to produce such a rotary assembly which is not only self lubricating but which in operation revolves substantially without vertical metallic contact, the pump building up suiicient pressure to elevate the rotating assembly and supporting it on the fluid in the pump housing because of the pressure built up therein by the pump.

'Ihe unitary motor, burner head and pump structure, all rotating on oil under pressure, substantially reduces noise and vibration.

Another object of the invention is to so construct the pump housing that when the level of fuel in the pump housing decreases upon the. start of the pump, yet the liquid seal drawing the fuel into the housing will not be broken with very considerable variations in the fuel level so that fuel is continuously supplied.

Another object of the invention is to assemble the moving parts as a unit which will therefore require a very small motor for their rotation and because of the so nearly complete absence of friction, the starting torque is very nearly negligible.

Other objects and advantages of the invention will be apparent from the following description and the accompanying drawings forming a part hereof, and will be pointed out in the claims.

In the drawings:

Figure 1 is vertical elevational embodying the invention,

Figure 2 is a vertical cross-sectional View of the lower portion of the motor and pump.

Figure 3 is a plan view of the fuel reservoir and pump housing.

Figure. 4 is an inverted plan view of the top of the. pump housing showing the pump runner therein.

view of a burner of the motor Figure 5 is a fragmentary sectional view on an enlarged scale showingthe fuel discharge from the rotating assembly.

In the drawings similar numerals refer to similar parts throughout the several views.

The stand I by means of uprights 2 supports the top section 3, having therein a vertically adjustable collar 4, which may be adjusted by the lever 5 and set screw 6; vertically adjustable thereon arms 'I holding screws 8 supporting springs 9 which in turn resiliently support the top- I2 of the main casing I Il. This casing is in three parts fastened together by long bolts IlY passing therethrough The removal of the top I2 and middle I3 of the casing exposes the fuel. chamber I4 vhaving therein the pump housing isin the center section I3 of the casing.

`The fuelv feeding and discharging assembly comprises a hollowshaft I"l= rotatably'mounted on a tubular shaft I 8. The top of the hollow shaft Il has thereon a fan I9-, a fuel receiving cup 20- and a fuel receiving plate 2| andl projecting thereabove, a stationary plate 22. Members 20. and 2l are xedly but removablyl attached to the assembly and. rotate with it,- but plate 22 is attached to a hollow stem 23 passing into and resting upon the upper end of the tubular shaft I 8. and it is therefore stationary. Fuel receiving plate 2l has additional fan vanes 24 projecting upwardly but not to contact with plate 22.

Tubular shaft I8 is mounted in the bottom of the fuel reservoir Ill and is held fast therein l by nut 25. The shaft opens into the lower compartment 26 formed bythe hollow nut 2l.

Hollow shaft I1 h as axial bearing surfaces i23 and 29 adjacentthe bottom and top thereof bearing on corresponding surfaces of tubular lshaft I8. `Shaft I'I likewise has a thrustbearing surface 30 grooved as at 3I to admit oil thereto, bearing on a shoulder 32v of tubular shaft I8.

Theuprights 2 have I 5. The motor stator Iii` In this passage 39 isplaced a fuel' has therein a passage of the shape of an involute 43, the portion of which furthest from the center leads to the passage 31. Centrally rotating in this space is the pump runner 44 having the vanes 45 thereon. This pump runner is screwed fast to, and thereby becomes a rigid part of, the fuel feeding and discharging assembly. The pump housing I has at its top two upwardly projecting collars 46 and 41. The pump runner fits rotatably in collar 46 and has projecting into the space between collars 46 and 41 and collar 41' extends above collar 48 to allow a certain elevation of the pump runner shaft on its bearings without being above the edge of the top of collar 41. On this rotating assembly immediately above the pump runner is, the rotor 49 of the motor and it is rigidly attached to the shaft I1. The collars, 46, 41 and 48, and their supports, are so spaced and held o by thrust bearing 30-32 as not to have any contact.

Fuel oil enters the fuel chamber from pipe 50 or other suitable openings, and passes under the collar 36 into the pump housing I5 in which its level is automatically maintained while the apparatus is at rest at a point slightly above the pump runner vanes by a level device old in the art and not shown. With the rotation of the pump runner, motion is imparted to the oil and 30 it is forced out of the pump housing through passages k31, 38, 39 and up through the tubular shaft I8. It passes on up through the central bore in the stem 23 yconnecting with the interior of the'tubular shaft I8 and it is forced out through openings 5I in stem 23.

The stem 23 being stationary. the oil flows down its side to bearing 28, through which some of it passes, and the rest is thrown outwardly byvrotating shaft I1, and then throughopenings 52 passing through hollow shaft I1 where it islthrown to the sides of the burnercup and-f the fuel then passes up the sides of the cup until itis discharged from the top thereof to the projecting edge of the plate 2l. The parts are so sized that a small quantity of the fuel oil is allowedv to flow down from the outside of the 10 jecting from its circumference a collar 48 pro-l when rotation begins, immediately the fuel level beings to fall because the oil begins to flow from the fuel chamber and pump housing. The oil level may decrease a very considerable degree, in fact almost to the bottom of collar 36 before the oil seal-would be broken and air admitted to the pump. This construction makes unnecessary any precision level control device and maintains the flow of fuel throughout the operation of the pump at a constant rate.

It will be apparent that the adjusting valve mechanism 4I may be removed along with the screen 40 for cleaning. 1t will likewise be ap- .parent that the nut 21 may be removed for cleaning the compartment 26 and the passage through the tubular shaft I8. The whole rotating assembly can be removed by lifting vertically through the large opening in top I2 upwardly 0 simply after taking off the stein 23 and top plate 22 and without the removal of any other member and it may of course likewise be replaced with equal facility after inspection or cleaning or repair. Should it be required the pump housing can be removed bodily by first removing the top and central portions of the casing and then removing the screws 53 holding the housing to the bottom of the fuel chamber. Thus the whole apparatus may be disassembled and assembled with facility and the skill usually possessed by the service men and there is nothing to become out of order or that may not be repaired in case of breakage.

A flexible coupling could be placed in pipeSIl to allow for vibration of the casing IIJ or the casing or fuel chamber could be placed in an oil basin or other oil container, in which the oil level is maintained, for the same purpose, but these features are believed to be old in the art and are not shown.

Having described one embodiment of the invention, it will be apparent that many modifications may be made therein and in different features thereof without departing from the invensembly is stationary,

'45A tion.

stem 23 from whence it passes down the outside- -Y m1' A veriiarota'ry liquid fuel feedmg appaia" of the tubular shaft I8 lubricating the same at s compmsm a moior stator a Casing .havuig a fuel chamber therein, a pump housing 1n said its two axial bearings and also at its thrust bearing. In its passage the oil goes between shafts I1 and I8 through grooves 3| and then between the lower enlarged section of shaft I8 chamber, a tubular shaft mounted in the bottom of said chamber and passing upwardly through said housing, the housing and casing having a continuous passage therein leading to the lower and the pump runner u' The flowing Oil also 55 'end of the tubular shaft, a fuel receiving asforms a coolant for the bearings. Any surplus sembly including a hollow shaft rotatably amount of on passing this Wav is draw-n into the W mounted on said tubular shaft a motor rotor top of the pump housing through pump runner 44. it is drawn by the axial suction of the centrifugal pump into its housing.

As the rotation of the assembly gathers speed the force exerted by the vanes upon the fuel oil in the pump housingr builds up sufl'ici ent pressure in the oil to raise the whole rotatingassembly from the thrust tlnuesthat assembly rotates on the oil in the pump housing without any vertical metallic conl tact-of the thrust bearing surfaces.

-The vanes 34 allow the; oil to flow under the collar 36 without foaming or surging and therefore without danger of breaking the fluid seal leading to the pump.

Although the fuel level maintaining device maintains the level at a point slightly above theV vanes of the pump runner while the as- 7 on said tubular shaft coacting with said stator to rotate said hollow shaft, a centrifugal pump 50 runner on the lower end of said hollow shaft,

operating 'in said housing to draw fuel axially thereinto from one side and means to seal the other side of said runner against the passage of fuel, said runner forcing the fuel radially and bealiner and aS the Speed C011- through said passage and tubular shaft to said shaft mounted in the bottom of said chamber and having an opening in the upper part thereof and below said opening an upwardly directed thrust bearing and adjacent each end sleeve bearings, a fuel receiving assembly including a 5 'hollow shaft rotatably mounted on said tubular shaft bearings,A a motor rotor on said hollow shaft coacting with said.` stator to rotateA said hollow shaft, means to force fuel received from said' chamber, through said tubular shaft to said opening, said shafts and bearings having a way therebetween through which fuel from said opening passes downwardly tothe surfaces of said bearings to lubricate the same.

3; A vertical rotary'liquid fuel feeding apparatus comprising` a casing, a motor stator therein, and in` its lower'part, a fuel chamber, a pump housing in said chamber having a fuel inlet in the bottom thereof, a tubular shaft mounted in saidcasing, a fuel receiving assembly including a hollow shaft rotatably mounted on and in operation being upwardly movable on saidA first named shaft, a motor rotor on said hollow shaft coacting with said stator to rotate said hollow shaft, a pump runner on the lower end of said hollow'shaft operating in said housing, thrust bearings on said shafts to limit the downward movement' of said hollow shaft, coacting seals on said pump runner and the upper side of said pump housing, said pump housing and casing having therein a` continuous passage leading to the bottom of said rstnamed shaft, said coacting` seals retaining the fuel from discharge therethrough and in the operation of the pump causing the fuel to elevate the hollow shaft from its thrust bearing whereby the hollow shaft rotates on a' body of fuel.

4. A vertical rotary liquid fuel feeding apparatusY comprising a casing, a motor stator therein and in its' lower part, a fuel chamber, a pump housing in said chamber having a fuel inlet in the bottom thereof, a tubular shaft mounted in said casing, a fuel receiving assembly including a hollow shaftv rotatably mounted on and in operation being upwardly movable on said first named shaft, a motor rotor on said hollow shaft coacting with said stator to rotate said hollow shaft, thrust bearings on said shafts to limit the downward movement of said hollow shaft, a pump runner on the lower end of said hollow shaft operating in said housing, saidhousing and casing having therein a continuous passage for fuel leading from the housing to the lower end of said first' named shaft, a multiple collared seal between the upper side of said pump housing and the pump runner, the outer collar being on the housing and being higher than the normal position of vertical movement of the pump runner to prevent the throw of fuel exteriorily by the runner, said collars being maintained'byA said thrust bearings out of contact one with the other.

5; A vertical rotary liquid fuel feeding apparatus comprising a fuel chamber, a pump housing in said chamber having a fuel inlet in the bottom thereof, a tubular shaft mounted in said chamber and passing upwardly through the fuel inlet in said housing, a fuel receivng assembly including a hollow shaft rotatably mounted on said tubular shaft, said housing and chamber having a. continuous passage therein leadingfrom the housing to the lower end of said tubular shaft, motor means to rotate said hollow shaft, a pump runner on said hollow shaft, operating in said housing, and radial vanes between the bottom of the housing and said fuel chamber to prevent the surging of fuel adjacent the pump housing entrance.

6. A vertical rotary liquid fuel feeding apparatus comprising a fuel chamber, a pump housing in said chamber, a tubular shaft mounted in said chamber and passing upwardly through said housing and having a fuel discharge opening therein, said housing and chamber havingl thereina continuous passage between the housing and the lower-'end ofthe tubular shaft, a fuel receiving assembly including a hollow shaft rotatably mounted on said tubular shaft, means to rotate said hollow shaft, a centrifugal pump runner on the lower end ofsaid hollow shaftV operating in saidV housing to force fuel through said passage and tubular shaft' to said' fuel receiving assembly, said shafts having a way therebetween, passing between said fuel discharge opening and the suction portion of said pump runner for the return of` fuel therethrough to the pump housing, a regulator valve in Said passage to adjust the volume of' fuel fed to said fuel receiving assembly, a greater volume of fuel being fed because of the return of fuel to the pump housing between saidy shafts.

7. A vertical rotary liquid fuel feeding apparatus comprising a fuel chamber, a pump' housing insaid chamber having at its bottom an axial fuel inlet and a collar tightly fitting in said inlet extending adjacent to the bottom of said chamber, a tubular shafty mounted in the' bottom of said chamber and passing upwardly through saidv collar and'housing, avfuel receiving assembly including a hollow shaft rotatably mounted on said 'tubular' shaft, motor means to rotate said hollow shaft, said housing and chamber having therein 'a passage between the housing and the lower 'end of` said tubular shaft7 a centrifugal pump runner' on said hollowshaft operating in said housing to force fuel through said passage, said i 'collar maintaining the vacuum created by said pump upon the fall in the level of the fuel in lsaid chamber to the'bottom of the said collar.

8'.. Avertical rotary liquid yfuel feeding apparatus comprising a casing, a motor statorV therein vand in its lower part, a fuel chamber, said casing having a central opening in the top thereof, a pump-housing in said chamber, a tubular shaft mounted'in saidY chamber and passing upwardly through said housing, a fuel receiving assembly including a hollow shaft rotatably mounted on said tubular sha-ft, a motor rotor on said hollow shaft coactingwith said stator to rotate s aid hollow shaft and a pump runner on the lower end of said hollow shaft, operating in said housing,

said housingand casing having therein a continulous passage betwen the housing and the lower end of said tubular shaft, said hollow shaft,- rotor and! pump runner being mounted as a unit and ibeing removable from said casing as a unit through said casingopening.

9. Al'iquid fuel feeding apparatus comprising Aa fuel chamber, a pump housing in said chamber having an'axial fuel inlet Vin the bottom thereof, a tubular shaft mounted in said chamber and passing upwardly through said housing, said housing and chamber having therein a continu-- ous passage between the housing and the lower end of the tubular shaft, a thrust bearing on said tubular shaft above said housing, a fuel receiving assembly including a hollow shaft rotatably mounted on said tubular shaft and bearing, means to rotate said hollow shaft, a centrifugal pump runner on and projecting downwardly bef low the lower end of said hollow shaft and said bearing int-o said housing and operating therein to draw fuel upwardly axially thereinto through said axial inlet and means to seal the upper side of said housing and runner against the discharge of fuel, said runner forcing fuel through said passage and tubular shaft to said fuel receiving assembly.

10. A vertical rotary liquid fuel feeding apparatus comprising a fuel chamber, a tubular shaft mounted in said chamber and having thereon a thrust bearing and adjacent each end thereof sleeve bearings, said shaft having an opening therein above said bearings, a fuel receiving assembly including a hollow shaft rotatably mounted on said tubular shaft bearings, means to rotate said hollow shaft, means to force fuel received from said chamber through said tubular shaft to said opening, said shafts and bearings having a way therebetween through which fue1 from said opening passes downwardly'to the surfaces of said bearings to lubricate the same.

11. A vertical rotary liquid fuel feeding apparatus comprising a fuel chamber, a pump housing in said chamber having a, fuel inlet in the bottom thereof, a tubular shaft mounted in said chamber, a fuel receiving assembly including a hollow shaft rotatably mounted onl and in operation being upwardly movable on said rst named shaft, means to rotate said hollow shaft, a pump runner on the lower end of said hollow shaft operating in said housing, thrust bearings on said shafts to support said hollow shaft, coaoting seals on the upper side of said pump housing and the pump runner, said housing and chamber having therein a continuous passage from the pump housing leading to the lower end of said tubular shaft, said coacting seals retaining the fuel from discharge therethrough and in the operation of the pump causing the fuel to elevate the hollow shaft from its thrust bearing whereby the hollow i shaft rotates on a body of fuel.

12. A vertical rotary liquid fuel feeding apparatus comprising a fuel chamber, a pump housing in said chamber having a fuel inlet in the bottom thereof, a tubular shaft mounted in said chamber, a fuel receiving assembly including a hollow shaft rotatably mounted on and in operation being upwardly movable on said first named shaft, means to rotate said hollow shaft, thrust bearings on said shafts to limit the downward movement of said hollow shaft, a pump runner on the lower end of said hollow'shaft operating in said housing, said pump housing and chamber having therein a continuous passage for fuel leading from said housing to the lower end of said tubular shaft, a multiple collared seal between the upper side of said pump housing and the pump runner, the outer collar being on the housing and being higher than the normal position of vertical movement of the pump runner to prevent the throw of fuel exteriorily by the runner, said collars being maintained by said thrust bearings out of contact one with the other.

13. An oil feeding apparatus comprising an oil chamber, a pump housing in said chamber, a tubular shaft mounted in the bottom of 'said chamber and passing upwardly through saidhousing, said pump housing and chamber having acontinuous passage therein leading from the housing and the lower end of the tubular shaft, a hollow shaft rotatably mounted on` said tubular shaft, thrust bearings on said shafts to support said hollow shaft, said tubular shaft having an opening therein above said bearings, a pump runner on -the lower end of said hollow shaft operating in said housing, means to rotate said hollow shaft and pump runner to force oil received from said chamber through said passage and Vtubular shaft to said opening, said shafts and bearings having a way therebetween through which fuel from said opening passes downwardly between them to lubricate them.

` 14. An oil feeding apparatus comprising an oil chamber, a pump housing in said chamber having a fuel inlet in the bottom thereof, a tubular shaft mounted in the bottom of said chamber and passing upwardly through said housing, said pump housing and chamber havinga continuous passage therein leading from the housing to the lower end of the tubular shaft, a hollow shaft rotatably mounted on and in operation being upwardly movable on said tubular shaft, thrust bearings on said shafts to limit the downward y movement of said hollow shaft, a pump runner on the lower end of said hollow shaft operating in said housing, coacting collars on the upper side of said pumpv housing and the pump runner forming a seal retaining the oil from discharge therethrough and in the operation of the pump causing the oil to elevate the hollow shaft from its thrust bearing wherby the hollow shaft rotates on a body of oil, means to rotate said hollow shaft and pump runner to force oil received from said chamber through said tubular shaft. l5. A vertical rotary liquid fuel feeding apparatus comprising a fuel chamber, a pump housing in said chamber, a tubular shaft mounted in said chamber and passing upwardly through said `housing and having a fuel discharge opening therein, said housing and chamber having therein a continuous passage between the housing and the lower end of the tubular shaft, a fuel receiving assembly including a hollow shaft rotatably mounted on said tubular shaft, means to rotate said hollow shaft, a centrifugal pump runner on the lower end of said hollow shaft, operating in said housing to force fuel through said passage and tubular shaft to said fuel receiving assembly, said shafts having a way therebetween, passing between said fuel discharge opening and the suotion portion of said-pump runner for the return of fuel therethrough to the pump housing.

RICHARD E. NEST. 

